JPS5957585A - Recorder and reproducer - Google Patents

Abstract

PURPOSE:To simplify the constitution of the titled device, by providing a means multiplexing the frequency of a digital single on a picture signal or a means reproducing the multiplexed digital signal so as to synchronize the clock period of the digital signal with the synchronizing period of the picture signal. CONSTITUTION:A recording head 3 and a reproducer head 6 are provided to a device recording and reproducing the picture signal, and an image pickup circuit 1, a recording circuit 2, a synchronizing signal supply circuit 12 and a code signal recording circuit 19 inputting an information signal are provided corresponding to a head 3. Further, a head 6 is provided with a reproducing circuit 7 and a code signal reproducing circuit 20, and the circuit 20 is provided with a narrow band filter 13, a detector 14, a threshold circuit 15 and a decoding circuit 16. Then, the digital signal is frequency-multiplexed on the picture signal by means of an oscillator 9 and an encoder 10 and the like in the circuit 19. Further, the multiplexed digital signal is reproduced at the circuit 20 so as to synchronize the clock period of the digital signal with the synchronizing period of the picture signal and to simplify the constitution of the recorder and reproducer.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image signal recording and reproducing apparatus, and is particularly suitable for a still image recording and reproducing apparatus.

2. Description of the Related Art So-called electronic cameras that combine a video camera with a magnetically or optically recording/reproducing device are known. Although this electronic camera cannot record video over long periods of time like a VTR using magnetic tape, it uses a micro-disk with a radius of several centimeters to record dozens of videos.
The object of the present invention is to capture and record about 100 still images, and the device is smaller, lighter, and easier to operate than a combination of a video camera and VTR0. Operability of the above-mentioned electronic camera or 7
An object of the present invention is to provide a small and inexpensive device that can multiplex and record information for improving four functions as a digital additional code signal on an image signal.

The information converted into an additional code signal includes (1) information on whether the image to be recorded is a field image or a frame image, (2) the track number of the disk corresponding to the image to be recorded, and (5) recording. Examples include information related to the recorded image, such as the date, 9 hours, and the temperature at 1 Liu Gui. The focus of the present invention is that since the information carried by these additional code signals is related to the image to be recorded, it is possible to perform frequency multiplex recording using means such as magnetic recording using the image signal as a bias. In this case, by associating the clock cycle of the additional code signal with the horizontal synchronization signal or vertical synchronization signal of the image signal, the clock signal causes complexity in the device for digital signal transmission.

The aim is to significantly simplify the framing operation.

In more detail, the digital signal is generated by turning on and off a single carrier wave or a plurality of carrier waves in a predetermined order at frequencies that are outside the image luminance signal band or chrominance signal band, or that can be considered to be substantially outside the band. The additional code signal is multiplexed and recorded as an additional code signal. This on/off period is set to be in a synchronous relationship with the horizontal synchronizing signal of the image signal, and the insertion position of the additional code signal on the time axis is determined based on the vertical synchronizing signal of the image.

Hereinafter, one embodiment of the present invention will be described in detail using the drawings.

FIG. 1 is a block diagram showing the configuration of an additional code signal multiplex recording and reproducing apparatus according to the present invention, and FIG. 2 is a conceptual diagram of waveforms for explaining the operation of this configuration. In Figure 1, 1 is an imaging circuit such as a video camera, 2 is a recording circuit, and 3 is a recording circuit.
4 is a recording head, 4 is a disc capable of magnetically or optically recording and reproducing, 5 is a reproducing head, 6 is a drive device for rotationally driving the disc, 7 is a reproduction circuit, and 8 is a reproduction saliva image signal. Output terminal, 19 code signal recording circuit, 2[1id
9 is an oscillator that oscillates at the carrier frequency of the additional code signal; 10-piece encoding circuit; 11 is an electronic switch; 12 and 871 supply a horizontal synchronization signal and a vertical synchronization signal from the imaging circuit 1; 13 is a narrow band filter 1411-1 having a resonance point at the oscillation frequency of the oscillator 9: a detector, a 15-piece threshold circuit, 1
6 is a decoding circuit, 17.18. 100. 121,
122, 161, 17 and 174 terminals. 21
22 is a mixing circuit, 25 is a recording amplifier, 71 is a modulation circuit for modulating the image signal into a format that can be recorded on the disk 4; 22 is a mixing circuit; 25 is a recording amplifier;
72 is a pickup amplifier, and 72 is an image signal demodulation circuit. At N1, the code signal recording circuit 19. The parts excluding the code signal reproducing circuit 20, that is, the imaging circuit 1, the recording circuit 2. Recording head 6, disc 4. Regeneration-・rad5. Drive device 6. Regeneration circuit 7. Synchronous signal supply circuit 12. The device consisting of the synchronization separation circuit 87 can be understood as a buffer amplifier for the mixing circuit 22 to which no signal from the code signal recording circuit 19 is input, and is therefore an image signal recording and reproducing device well known to those skilled in the art. Approximately 100 to 100 still images can be recorded and played back on tracks set to Many 1
The code signal recording circuit 19 is used to record the information on the disk 4 by reproducing and decoding the additional code signal multiplexed on the disk 4 and outputting an output signal corresponding to the information input to the terminal 17. This is a circuit that outputs to the terminal 18 or a code signal reproducing circuit.

The operation of these circuits will be explained with reference to the waveform diagram in FIG.

First, the recording operation of the additional code signal will be explained. Second
<3) and (b) in the figure are respectively synchronous signal supply circuits 12
The output waveforms of the vertical synchronization signal and horizontal synchronization signal observed at terminals 121 and 122 in Fig. 1 are schematically shown. It has a pulse width three times that of the horizontal synchronization signal, and its period is 262.5 times the period of the horizontal synchronization signal.
It's double. To simplify the explanation hereafter, we will use the vertical synchronization signal (
2nd: 1F1. No. 21-1.
3rd)(,=·, nth H+ ``' + 26th s, H. The state of this is shown in FIG. 2(b). Encoding circuit 1
At 0, these synchronization signals output from the synchronization signal supply circuit 12 and the information signal input to the terminal 11 are scanned.
A predetermined digital code (here, since w'J is simple, an integer k is used as the bit information code),
As shown in Fig. 2 (c), the horizontal synchronization number 4g period corresponds to the time length of 1 bit, and is sequentially output from the predetermined mH (m I4 integer) to the (m+k)H'. do. This example is observed and measured at terminal 100 in FIG.
Two fakes are shown in Figure 2(c). In the same figure, lc:F8
, rn = 1, that is, the digital code ir+o1iioi is output from the 1st H to the 8th H. The output signal of this encoding circuit 10 is the terminal iQ[)'
Since the electronic switch 11 opens and closes in response to the input digital code, the oscillator 9 is connected to the mixing circuit 22 as shown in FIG. 2(d). An output i-g signal is supplied corresponding to this digital code, and a note-beating code signal frequency-multiplexed with the image signal is recorded on the final disc 4. Oscillator 9 here
The oscillation frequency of the modulated image (image signal) which is the output signal of the modulation circuit 21 is selected to be a frequency that is outside or substantially outside the frequency band of the modulated image signal, and the mixing ratio thereof is determined as the reproduction image. Alternatively, it is selected to a level that does not cause interference based on nonlinear distortion in the recording/reproducing system.

Fig. 7 is a schematic diagram showing the recording signal to the ellipse @ 4 after the additional code signal is multiplexed as described above, that is, the recording current flowing to the recording head 4, on the frequency axis. The luminance signal component of No. 1L■ is the center frequency group 7.
Mllz, I'i' of band approximately 9■Z M modulated wave 9 signal component has a center frequency set of 1.2MHz band approximately 2Ml
lz AM or FM modulation wave, additional code signal is approximately 15
0) jlz stop string wave. According to experiments, the mixing level of the additional code signal is about -3 the amplitude level of the luminance signal component.
If the oscillation frequency of the oscillator 9 is approximately ino 11z to 300K11z, no interference will occur to the playback screen, and the additional coat signal can be detected and played well. In addition, even if interference occurs due to the mixing ratio of the additional code signal increasing during production or due to changes over time, in order to keep this to at least one wave, the oscillator 9
The oscillation frequency is the reciprocal of the horizontal synchronization signal period (integer + i)
It is preferable to obtain a frequency interleaving effect by selecting twice as much. The above is the multiplex recording operation of additional code signals.

The operation of detecting and reproducing the additional code signal multiplexed on the disc 4 will now be described.

The additional code signal multiplexed on the disk 4 is converted into an electric signal together with the image signal by the playback head 6, amplified by the pickup amplifier 71, separated from the image signal by the narrowband filter 3, and then sent to the detector 14. The thread/wave detected by the
The signal passes through the Jordo circuit 15 and is input to the decoding circuit 16.

This input signal is clearly an additional code synchronized with the horizontal synchronization signal output from the encoding circuit 10 during the recording operation. The decoding circuit 16 inputs the vertical synchronization signal and the horizontal synchronization signal separated and extracted by the synchronization separation circuit 87 from the reproduced image signal output from the decoding circuit 72 via terminals 173 and 174i, respectively. The additional code signal input to 161 is reproduced and decoded, and an output signal corresponding to the decoded information is output to terminal 1B. When the S/N ratio of the output signal of the wave detector 14 is poor, pulse-like noise may be mixed into the output signal of the threshold circuit 15, making it easy for the decoding circuit 16 to malfunction. in this case,
For example, a low-pass filter and a waveform shaping circuit may be inserted between the threshold circuit 15 and the decoding circuit 16, or a low-pass filter may be inserted between the detector 14 and the threshold circuit 15.
It is preferable to avoid supplying a waveform that produces both 0 and 10 in the horizontal opening signal period.

If the S/N of the output signal of the detector 14 is so poor that stable decoding cannot be performed even with the above-mentioned means, or (
During the recording operation, the mixing ratio of the mixing circuit 22 can only be increased to a level that does not cause any disturbance to the screen. ) If the clock frequency of the additional code signal can be lowered below one horizontal opening signal period because the number of information pits to be transmitted is small,
The S/N can be increased by doubling or more than twice the clock of the additional code signal and narrowing the pass band of the bandpass filter 16 to a commensurate extent, or by reducing the decoding in the decoding circuit 16 to an apparent one horizontal opening period. Decoding is performed while maintaining the signal period or less, and errors in decoding are eliminated by applying majority logic. Means for preventing malfunctions due to the above-mentioned noise must be determined in advance at the time of designing this recording/reproducing apparatus.

The above is the reproduction and decoding operation of the additional code signal.

FIG. 4 shows an embodiment of the encoding circuit 10. In the same figure, 1
000 shift register, 1001&'i buffer register, 1002 and 1003 are terminal 171 respectively.
This is a button memory that generates a coded button corresponding to the information input to the terminal 172. Terminal 171. terminal 172td
Both terminals are terminals for inputting information, and in the embodiment shown in FIG. 1, these terminals were shown as terminal 1 as the first terminal. In the figure, when information is input to the terminals 171°1.72, the corresponding button memories 1002 and 100
The code button is read from 3 and buffer register 10
01 to a predetermined pit position. shift register 1
The contents of the buffer register 1001 are transferred to 002 at the rising edge of the vertical synchronizing signal input to the terminal 122, and the transferred contents are shifted by one pit at the rising or falling edge of the horizontal synchronizing signal pulse input to the terminal 122. Output to terminal 100.

Therefore, an additional code signal corresponding to the information input to the terminals 171 and 172 is output to the terminal 100.

FIG. 5 shows an embodiment of the code signal reproducing circuit 20. In the same figure, 1601 is a shift register, 1iSO2 is terminal 1
The contents are cleared by dividing the horizontal synchronizing signal pulse inputted to 74. 1604 and 1614 are respectively the button memories in which all the buttons corresponding to the contents of the button memory 1002゜1[]03 in Fig. 4 are stored. , 1606 and 1616 The decoders 1605 and 1615 detect that the count value of the counter 1602 has reached a predetermined value, respectively. This is a comparator that outputs a coincidence signal to terminals 181 and 182. In this configuration, the additional code signal which is the output signal of the threshold circuit 15 is inputted to the shift register 1601 in time series from the terminal 161, and its contents are shifted at the period of the horizontal synchronization signal inputted to the terminal 174. The input additional code signal passes through the contents of the shift register while being shifted in time series. On the other hand, the decoder 16031613 detects the position of the shift register 1000 into which the contents of the button memories 1002 and 1003 shown in FIG. 4 are to be inserted, and
When each is detected, each comparator 1605, 1615 determines whether the contents of the shift register 1601 and the contents of the button memory 1604, 1614 match, and the result is sent to each terminal 181, 182.
Output to.

The above is an embodiment of the additional code signal encoding/decoding circuit of the present invention. In the above example, these circuits were configured using digital logic circuits, but they can be implemented using separate microcomputers, or one microcomputer if the recording and reproducing devices are built in the same package. In this case, the microcomputer can be, for example, a one-chip four-pit microcomputer IMC844 or MMC34,5 manufactured by Hitachi.

As an example of how these circuits can be realized using a microcomputer, a case will be described in which two encoding circuits 10 are constructed in contrast to the configuration shown in FIG. The button memories 1002 and 100 in FIG. 4 can be used as part of a read-only memory (hereinafter referred to as ROM), which is a program storage area of a microcomputer, or a programmable logic array (hereinafter referred to as r&PLA).
It is expressed as ) is allocated in advance, and when a signal is input to the input terminals corresponding to the input terminals 171 and 172i, which were also allocated in advance, the buffer register 100
The content of the ROM is transferred to a predetermined address of the random access memory (hereinafter referred to as RAM) corresponding to 1, and the vertical synchronizing signal pulse is input to the input terminal corresponding to terminal 121. Wait there. Counting is started at the period of the horizontal synchronizing signal input to the input terminal corresponding to the input terminal corresponding to the terminal 121 (when the Q pulse is input to the terminal G), and (L O, M or P j −
It monitors whether it reaches a preset count value that is assigned in advance to iΔ, and when it reaches this count value, the contents of RA R4 are counted and ET''I 1iJ1
Then, the signals are sequentially output from the output terminal corresponding to terminal 100. 12. The above is the configuration method of the encoding circuit 10 using a microcomputer. The above-mentioned R, O? circuit 16 is also built into the microcomputer. ARAM,,PLA,
By opening the input/output terminals fully, a configuration similar to the above can be performed. In this way, the encoding circuit 10.
When the decoding circuit 16 is realized by a microcomputer, the same microcomputer performs logical processing and judgment of information from each part of the device until the information is supplied to the input terminals 171, 172, and output terminals 181, 172, etc. 182
Information processing such as control commands to each part of the device that should be performed in response to the output signal displayed on the screen, and digital signal processing and control that are not related to the additional code signal but are essential in configuring the electronic camera. Since all nine circuits can be easily integrated, these circuits can be constructed at very low cost and in a small space. Therefore, it is essential to construct the device in a compact and lightweight manner through high-density component mounting. This effect is particularly great for electronic cameras. In the above-mentioned implementation example of the present invention, 1 bit time length of the additional code signal was explained as 1 horizontal period signal period, but this is not an absolute condition, and 2 horizontal periods As described above, the horizontal synchronizing signal period may be equal to or longer than the synchronizing signal period, or may be an integer fraction of the horizontal synchronizing signal period. Rather, the intention of the present invention is to eliminate the need for a high-precision clock signal generation circuit required for digital signal transmission by associating the 1-pit time length with the necessary and special horizontal synchronization signal period in the image signal recording/reproduction processing device. The purpose of this process is to make the device smaller, lighter, and lower in cost. The same intention is to clarify the absolute address of each horizontal synchronization signal by using a necessary and special vertical synchronization signal in the image signal processing device, and to use this to make the encoding and decoding processing of additional code signals easier and cheaper. There is also something to tighten.

In addition, in one embodiment of the present invention explained using FIG.
Although the additional code signal is configured by opening and closing the slave switch 11, that is, turning on and off the oscillator 9, as another example, in order to further improve the reliability of decoding the additional code signal, an oscillation other than the oscillator 9 is used. Another oscillator having a certain frequency may be provided, and instead of the electronic switch 11, another electronic switch may be provided that passes the signal from one of these two sets of oscillators. In this case, the code signal regeneration circuit 20 is provided with another set of configurations corresponding to the configuration from the narrowband filter 13 to the threshold circuit 15 via the detector 14, and its selected frequency matches the above-mentioned added frequency l. and the decoding circuit 16 is the threshold circuit 1.
Instead of determining the presence or absence of the output signal No. 5, it is configured to determine which of the two sets of threshold circuits the signal is input from. In this case, whereas the embodiment shown in FIG. 1 is an on-off keying transmission of digital signals, it can be interpreted as a frequency keying transmission. That is, in this configuration, instead of providing two sets of oscillators, the oscillation frequency of the oscillator 9 may be keyed by the output signal of the encoder circuit 10, and instead of providing two sets of configurations ranging from bandpass filters to threshold circuits. The decoding circuit 16 may be configured to include a frequency discrimination circuit and operate the decoding circuit 16 using the output signal thereof.

Incidentally, in the above embodiment, the horizontal synchronization signal period in which no additional code signal is assigned within the vertical synchronization signal period was not explained, but the electronic switch 11 in FIG. 1 remains closed during these periods. Good to keep. That is,
In this way, at least in this section, the detector 1
4 corresponds to the output signal level of the reproducing head 6. Therefore, the reproducing head 6 is structured to be able to be controlled to move in the radial direction of the disc 4, and the detector 14
The playback head is moved to disk 4 so that the output signal amplitude is maximized.
By adding a closed loop for controlling the movement of the head in the radial direction to the configuration shown in FIG. 1, a so-called playback head tracking loop is constructed, so that the best possible image playback is always possible.

In the recording and reproducing apparatus according to the present invention, the additional code signal is set so that the electronic switch 11 is not opened in all horizontal synchronization signal periods in the vertical synchronization signal period, regardless of the combination of input information. Then, if the threshold circuit does not produce any output signal during the reproduction operation, it can be determined that the reproduction trunk at that point in time of the disk 4 is unrecorded, so a means for detecting this state is added to the decoding circuit 16. As a result, if a magnetic sheet is used as the circle@4 due to double copying due to an erroneous operation, there will be a significant deterioration in image quality. ) can be prevented from occurring, and after removing the -n disk 4 from the device without recording completely on all tracks,
When the disk 4 is mounted on the same or another device again and recording is continued anew, it is possible to locate the beginning of an unrecorded track.

In addition, in the detailed description of the present invention, an electronic switch is added inside the image signal demodulation circuit 72 or immediately before the output terminal 8, and the opening and closing of the electronic switch is controlled in the state of the decoding circuit 16, and all or Until the decoding of a predetermined specific additional code signal and the signal processing or device control based on it are completed, all terminals 8 of the reproduced image signal are
If the configuration does not lead to this, it is possible to avoid causing discomfort to the user of the device due to displaying an incompletely reproduced image.

In the above description of one embodiment of the present invention, the present invention was applied to a device using a magnetically or optically recordable and reproducible disk; In other words, it is easy to say that the present invention can be applied.

In addition, in the embodiment 1 described using FIG. 1, since a video camera was used as the imaging circuit 1, the encoding circuit 10
In the above, a horizontal synchronization signal and a vertical synchronization signal were introduced from a synchronization signal generation circuit of a video camera via a synchronization supply circuit 12, but the image pickup circuit 1 is used to input an image signal received by a television, or an image once recorded on a VTR or the like and played back. When using a device to which a signal is supplied, it is unnecessary to use a synchronous separation circuit that is the same as or similar to the synchronous separation circuit 87 as the synchronous supply circuit 13.

[Brief explanation of drawings]

a i 1 rrr A block diagram showing the configuration of an embodiment of the recording/reproducing apparatus according to the present invention, FIG. 2 is a conceptual diagram of waveforms to explain the operation of the configuration, and FIG. 6 is a diagram showing the frequency axis where signals are multiplexed. FIG. 4 is a block diagram showing an implementation example of an encoding circuit, and FIG. 5 is a block diagram showing an example of a decoding circuit. 1... Imaging circuit 2... Recording circuit 6... Recording head 4... Disk 5... Drive device 6
... Reproduction head 7 ... Reproduction circuit 9 ... Oscillator 12 ... Synchronization supply circuit 16 ... Narrow band filter 14 ... Detector 15 ... Threshold circuit 10 ... Encoding circuit 16.・Decoding circuit 19...
- Code signal recording circuit 20... Code signal reproducing circuit 1000... Shift register 1001... Buffer registers 1002, 1005... Bang memory 1601...
Shift register 1602... Counter 1603, 1613... Decoder 1604, 1614... Batamemory agent patent attorney
Susuki 1) Ri Muro Li, 28 Ko 30 Bureau 5 Countercount 4th Prisoner R Father Proceedings Amendment (Method) Case Description 1981 Patent Application No. 76709 Title of Invention
Person who corrects recording/playback equipment/IT'? + and one friend Patent applicant's name (Doil) 510141 Type name Hitachi ``J-Sakusho agent Subject of personal amendment Specification

Claims (1)

[Claims] A device for recording and reproducing an image signal, comprising means for frequency multiplexing a digital signal on the image signal or means for reproducing the multiplexed digital signal, and a clock cycle of the digital signal is synchronized with a horizontal synchronization signal cycle of the image signal. A recording/reproducing device characterized by being in a relationship.